Renal vascular and excretory responses to prostaglandin endoperoxides in the dog

To determine whether the prostaglandin endoperoxides PGG2 and PGH2 have direct effects in the kidney, PGG2 and PGH2 were administered into the renal artery of anesthetized dogs and their effects were compared to those of PGE2. Like PGE2, PGG2 and PGH2 induced a dose-related renal vasodilation. A 50% increase in the renal blood flow was observed with 0.05 microgram/kg body wt of PGE2 and with four- and sixfold higher doses of PGH2 and PGG2, respectively. Infusion of all three compounds at doses inducing a 50% increase in the renal blood flow resulted in 1) increases in blood flow to all cortical areas, with the greatest increase occurring in the juxtamedullary area, 2) diuresis with no change in the glomerular filtration rate, and 3) natriuresis and kaliuresis. In vitro incubation of PGH2, a maneuver known to result in its conversion to other prostaglandins, had no influence on its renal effects. The data indicate that PGH2 and PGG2 are biologically active when infused into the renal artery of the anesthetized dog and suggest that the endoperoxides exert their effects after bioconversion to other prostaglandins.